Plunder piled so haphazardly (7)
I believe the answer is:
despoil
'plunder' is the definition.
(I know that plunder can be written as despoil)
'piled so haphazardly' is the wordplay.
'haphazardly' indicates anagramming the letters.
'piled'+'so'='piledso'
'piledso' with letters rearranged gives 'DESPOIL'.
(Other definitions for despoil that I've seen before include "sack" , "strip" , "Plunder (a place)" , "Plunder - I sloped (anag)" , "Steal from (a place)" .)